3v4l.org

run code in 300+ PHP versions simultaneously
<?php $data = Array( Array ( 0 => 'Charcoal', 1 => 'Natural Gas', 2 => 'Combo' ), Array ( 0 => 'Charcoal', 1 => 'Propane', 2 => 'Combo' ), Array ( 0 => 'Charcoal', 1 => 'Propane', 2 => 'Natural Gas', 3 => 'Combo' ), Array ( 0 => 'Natural Gas', ), Array ( 0 => 'Natural Gas', 1 => 'Propane', ), Array ( 0 => 'Propane', ), Array ( 0 => '660 sq. inches' ), Array ( 0 => '740 sq. inches' ), Array ( 0 => '761 sq. inches' ), Array ( 0 => '788 sq. inches' ), Array ( 0 => '792 sq. inches' ) ); $result = array_unique(call_user_func_array('array_merge', $data)); var_dump($result);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.6 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
array(9) { [0]=> string(8) "Charcoal" [1]=> string(11) "Natural Gas" [2]=> string(5) "Combo" [4]=> string(7) "Propane" [14]=> string(14) "660 sq. inches" [15]=> string(14) "740 sq. inches" [16]=> string(14) "761 sq. inches" [17]=> string(14) "788 sq. inches" [18]=> string(14) "792 sq. inches" }

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